Molecularly Designed Additives for Chemically Deconstructable Thermosets without Compromised Thermomechanical Properties.

"Drop-in" additives that introduce chemically cleavable bonds into thermosets without compromising thermomechanical properties could enable triggered material deconstruction and enhanced sustainability. While the installation of cleavable bonds into the strands of the commercial thermoset polydicyclopentadiene (pDCPD) using comonomers facilitates chemical deconstruction, these additives can lower the material's glass transition temperature ( T g ). By contrast, the installation of cleavable crosslinkers into pDCPD can maintain or potentially increase T g but does not facilitate chemical deconstruction. Here, we introduce "strand-cleaving crosslinker" (SCC) additives that provide cleavable pDCPD network junctions. Notably, pDCPD samples featuring 10% v/v of SCCs can be deconstructed under mild conditions to yield soluble products and display a 48 °C higher T g than analogous decontructable pDCPD made using cleavable comonomers and an equivalent T g to virgin pDCPD. The SCC concept could offer a general strategy for the design of chemically deconstructable thermoset materials without compromise on thermomechanical performance.